Everyone loves a story about the human brain. Whether it’s what music is supposed to make us buy in the supermarket, or whether doing crosswords will make you live longer. But the media doesn’t always get it right in reporting on how the most complex organ in the known universe operates.

In this column, I will take reports on neuroscience and psychology from the daily news and see how they stack up scientifically. I’ll be looking at the details of how these experiments are really done, and interrogating what they really tell us about human behaviour and the brain, beyond how they get reported in the papers.

To kick off, here’s my take on whether a pair of staring eyes can really deter bike thieves.

The headlines

The story

A picture of a large pair of eyes triggers feelings of surveillance in potential thieves, making them less likely to break the rules.

What they actually did

Researchers put signs with a large pair of eyes and the message “Cycle thieves: we are watching you” by the bike racks at Newcastle University.

They then monitored bike thefts for two years and found a 62% drop in thefts at locations with the signs. There was a 65% rise in the thefts from locations on campus without signs.

How plausible is it?

A bunch of studies have previously shown that subtle clues which suggest surveillance can alter moral behaviour. The classic example is the amount church-goers might contribute to the collection dish.

This research fits within the broad category of findings which show our decisions can be influenced by aspects of our environment, even those which shouldn’t logically affect them.

The signs are being trialled by Transport for London, and are a good example of the behavioural “nudges” promoted by the Cabinet Office’s (newly privatised) Behavioural Insight Unit. Policy makers love these kind of interventions because they are cheap. They aren’t necessarily the most effective way to change behaviour, but they have a neatness and “light touch” which means we’re going to keep hearing about this kind of policy.

Tom’s take

The problem with this study is that the control condition was not having any sign above bike racks - so we don’t know what it was about the anti-theft sign that had an effect. It could have been the eyes, or it could be message “we are watching you”. Previous research, cited in the study, suggests both elements have an effect.

The effect is obviously very strong for location, but it isn’t very strong in time. Thieves moved their thefts to nearby locations without signs - suggesting that any feelings of being watched didn’t linger. We should be careful about assuming that anything was working via the unconscious or irrational part of the mind.

If I were a bike thief and someone was kind enough to warn me that some bikes were being watched, and (by implication) others weren’t, I would rationally choose to do my thieving from an unwatched location.

Another plausible interpretation is that bike owners who were more conscious about security left their bikes at the signed locations. Such owners might have better locks and other security measures. Careless bike owners would ignore the signs, and so be more likely to park at unsigned locations and subsequently have their bikes nicked.